The WJWW is a non-profit public benefit corporation consisting of the member municipalities of the Village of Mamaroneck, Town of Mamaroneck and the Town/Village of Harrison.  The WJWW supplies water on a retail basis to its member municipalities and to portions of the City of Rye and the City of New Rochelle.  It also sells water on a wholesale basis to the Village of Larchmont and Suez Water Westchester.

The WJWW serves a retail population of 59,629 persons through 14,682 service connections.  In 2015, the WJWW purchased 5.08 billion gallons of water and sold 4.13 billion gallons of it to consumers. The difference of approximately 950 million gallons or 18.7% of total water purchased from NYC is classified as unbilled water (formerly referred to as unaccounted water). Unbilled-water consists of water lost due to leaks and main breaks, under-registration of meters, use at fires and hydrant flushing.  The daily average water treated and pumped into the distribution system was 13.9 million gallons per day.  The highest single day was 23.7 million gallons.

The WJWW does not have any rate-making power.  Each of its member municipalities establishes its own rate schedule.  Therefore, the cost of water varies by community.  Assuming the average annual usage is 100,000 gallons, the equivalent of 134 hundred cubic feet, the annual cost based on rates in effect as of July 2015 for a typical customer having a 5/8" meter, consuming water evenly over the year, would be:

Village of Mamaroneck$757.86
Town of Mamaroneck$806.34
Town of Harrison$751.32
City of Rye$1,057.86*
City of New Rochelle$1,052.90*

*The cost of water in the outside districts of the City of Rye (Subject to Village of Mamaroneck water rates) and the City of New Rochelle (Subject to Town of Mamaroneck water rates) are higher than those of their associated member municipalities, since these cities tax the water mains of the WJWW, whereas the WJWW water mains within its member municipalities are tax exempt.